Climate Change Linked To Surge In India Suicides

An Indian farmer from Tamil Nadu state wearing a necklace of human skulls representing suicides by agricultural workers gestures during a protest with other farmers in New Delhi on March 15, 2017. More than 200 farmers have committed suicide in Tamil Nadu in recent months following crop failure due to poor rainfall and inadequate water for irrigation. (PRAKASH SINGH/AFP/Getty Images)

New research seems to confirm what some have suspected: climate change is behind a surge in suicides in India over the last four decades, particularly of farmers.

Human-caused global warming has led to 59,000 suicides in India since 1980, according to research published yesterday by Tamma Carleton, a doctoral fellow at the University of California, Berkeley, who predicts an additional 67 suicides occur for each 1ºC (1.8ºF) increase during a single day during the growing season.

The suicides appear to be motivated by widespread crop loss caused by the increased heat, and resulting farmer debt.

"Farmer suicides in India have been at epidemic levels, with widespread controversy over the causes and government responses," said Solomon Hsiang, a professor of public policy and the head of Berkeley's Global Policy Laboratory, where Carleton conducts her research. "This analysis provides the first evidence that rising temperatures are partially responsible for the current situation."

Carleton compared temperature increases during India's growing season with temperature increases in the nongrowing season, and found that heat in the growing season matches the increase in suicides.

"The differential response of suicide to temperature in the growing and nongrowing seasons is consistent with an agricultural channel in which heat damages crops, placing economic pressure on farming households, members of which may respond to such hardship with suicide," she writes in PNAS. "These crop losses may also permeate throughout the economy, causing both farming and nonfarming populations to face distress as food prices rise and agricultural labor demand falls."

Carleton acknowledges that she cannot directly test the hypothesis that climate-induced hardship drives farmers to suicide, and that she cannot rule out other factors that might correlate with both climate and suicide. But she doubts any other factors can challenge the robustness of the effect she finds between growing season temperature and suicide rates across different Indian states and conditions.

Carleton confines her research to India, where the rise in suicide rates has been remarkable, but she suggests her findings reveal important implications for the relationship between climate change and human hardship globally. India is home to one-fifth of the global human population, she notes, and she found no evidence India's population has adapted to climate change over the past half century to offset these climate-induced hardships.

"It is possible that a similar link between climatic conditions which damage crops and suicide rates may exist in locations where populations are heavily dependent on agricultural income," she told me via email, "and where social safety nets to insure against these severe income shocks are minimal."

Her research suggests that public policies, such as policies that make crop insurance available, could help prevent suicides, and it presses policymakers to consider suicide a social cost of carbon emissions.

"Suicide is a heartbreaking indicator of human hardship," Carleton said, "and the finding that this phenomenon is affected by a changing climate implies that it is essential to quantify its effect and consider this relationship as we build climate policy for the future."

Suicide is not the only cause of death exacerbated by climate change in India. Economist Michael Greenstone reported at the Aspen Ideas Festival in June that each additional hot day in India increases mortality by 0.7 percent. "Just one extra day," Greenstone said. "And India's probably going to get 30 or 40 of those by the end of the century."

This map shows the increase in suicides across India that can be attributed to global warming.Berkeley Global Policy Laboratory

I've covered the energy and environment beat since 1985, when I discovered my college was discarding radioactive waste in a dumpster. That story ran in the Arizona Republic, and I have chased electrons and pollutants ever since, for dailies in Arizona and California, for alt...